Navigation

Ask Dr Gary: Science of sleep still a mystery

6:00 AM Wednesday Jan 16, 2013

Not saved

Facebook0

Twitter0

LinkedIn0

Google+0

Email

Print

I watched a movie called The Machinist recently. It's about a man with insomnia who didn't sleep for a whole year. It got me wondering how long can a person go without sleep? Can anyone not sleep for a year and survive? - AJ

The 1965 Archives of Neurology reported on a 17-year-old from San Diego who voluntarily went for 11 days without sleep and recovered fully. Longer periods have been reported, but this one was unique because it was so well documented by a sleep physician from Stanford University and a lieutenant-commander at the US Naval medical centre.

The other notable thing was that the kid, Randy Gardner, took no stimulants, not even caffeine.

He ultimately was fine but, like others who have tried it, by day three he began losing his mind, having vivid hallucinations and losing track of even simple thoughts. By the final day, number 11, he was still walking and talking, but he'd lost most of his short-term memory, had slurred speech, had trouble with dizziness and his hallucinations had worsened. After almost 15 hours of deep sleep, though, he recovered.

There are reports of other people who have stayed awake for years because of insomnia, but the definition of "awake" is the problem. Tired people can "microsleep" - bursts of sleep lasting from a fraction of a second up to half a minute. These episodes are frequent, and go largely unnoticed, although they can be picked up on electroencaphalograms. Insomniacs are getting sleep - just in tiny, unnoticed and unsatisfying quantities.

Last year, researchers studied individual neurons in live rats' brains, and found that from a batch of say, 20 neurons, one or two may actually be asleep for short periods.

So sleep is a tricky concept. The exact point at which we go from asleep to awake is also difficult to pin down.

We know from numerous studies that after even one night without sleep, your cognitive performance will equal a drunk's, but you won't be aware of it. Three nights without sleep, and you'll experience heavy hallucinations. Beyond that, you may seem superficially "awake" but parts of your brain will be having rolling blackouts.